Reclosable Package Using Low Tack Adhesive

ABSTRACT

A package configured to reclose after an initial opening and reduce head space in the package includes a plurality of walls with a pair of opposing wall segments, where each of the opposing wall segments have top and bottom edge portions, a width, a height, and facing inner surfaces. The plurality of walls are sealed to form an interior cavity to receive items therein, the cavity bounded by a bottom wall segment and an initially removably sealed upper mouth. The package further includes a low tack adhesive zone disposed across the entire width and extending from adjacent the mouth toward the bottom wall segment along at least a majority of the height of the facing inner surfaces. The adhesive zones have a greater affinity for adhesion to each other than to the items and permit the package to be repeatedly reopened and reclosed at a plurality of different heights to minimize headspace.

CROSS-REFERENCE To RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 61/308,540 filed Feb. 26, 2010; U.S. Provisional Application Ser.No. 61/317,592 filed Mar. 25, 2010; U.S. Provisional Application Ser.No. 61/407,406 filed Oct. 27, 2010; and U.S. Provisional ApplicationSer. No. 61/407,409 filed Oct. 27, 2010, all of which are incorporatedherein by reference in their entirety.

FIELD

A reclosable package is described herein and, in particular, areclosable package using a low tack adhesive to reclose the package.

BACKGROUND

A package, such as a package made of flexible material, is commonly usedto store items during transportation, storage, and consumption by auser. A common type of prior package is mass-produced from a web of filmmaterial. The web is formed into a continuous tube by sealing thelongitudinal edges of the web together. This continuous tubular packagecan then be singulated into smaller packages by sealing and cuttingtransversely across the tubular package in the region of the transverseseals.

Commonly, prior packages initially store the items within a sealedinterior cavity prior to purchase by a consumer. The consumer can thenbreak one of the seals or remove a corner of the package to access theinterior cavity and the items therein. One issue that arises after theinitial breaking is how to effectively reclose the package. Reclosingcan be achieved by using interlocking zipper strips, including thosewith a slider mechanism, such as discussed in U.S. Pat. No. 5,007,143.This solution, however, is limited to reclosing the package along thezipper strips at the top of the package, which results in headspacecreated as the items are removed. Furthermore, the cost of adding thezipper strips can increase the cost of the package.

If a package is provided without a reclose feature, a common practice isto fold the edges of the package over to reduce the headspace above theitems and close the broken seal. A clip can then be applied over thefolded material to hold the package in this closed state. This practice,however, often does not sufficiently close the package and if theconsumer does not have a clip, the package can unfold and fully exposethe items.

SUMMARY

A package is described herein that is configured to reclose at aplurality of different locations progressively closer to the bottom ofthe package after initial opening and subsequent removals of items fromwithin the package in order to reduce headspace in the package above theitems. The package includes a pair of opposing walls each having atleast one adhesive zone at least partially containing a low tackadhesive extending substantially across the entirety of the width of aninterior of the package. When the opposing walls are pressed together,the adhesive zones reclose the package. The low tack adhesive isparticularly effective in reclosing the package by having a greateraffinity for itself than for the items stored therein, allowing the lowtack adhesive to adhere to itself even if the low tack adhesive comesinto contact with the items. As the items are sequentially removed fromthe package and the package reclosed, headspace is created above theitems. The size of the adhesive zones can permit the opposing walls tobe pressed together at a height closely adjacent to the items to reclosethe package at that location, thereby minimizing the headspace in thepackage. The package can further include one or more separable areas ofweakness that allow an upper portion of the package to be removed abovea reclosed portion of the package.

This package can provide a number of advantages. For example, as aresult of reducing headspace in the package, air in the reclosed packagecan be reduced. Additionally, if the adhesive zone is disposed along aplurality of heights of the package, the package can be reclosed at theplurality of heights, allowing the package to reclose closely adjacentthe items stored therein as it is being sequentially removed at discretetimes. Finally, the optional areas of weakness can allow excesspackaging to be removed which provides easier access to the items.

In one aspect, the package can include a plurality of walls with a pairof opposing wall segments, where each of the opposing wall segments hastop and bottom edge portions, a width, a height, and facing innersurfaces. The plurality of walls are sealed to form an interior cavityto receive the items. The cavity is bounded below by a bottom wallsegment and above by an upper mouth that is initially sealed, but isremovable to permit initial access to the items. The package furtherincludes a low tack adhesive zone disposed on and substantially acrossthe entire width of the opposing inner surfaces. The adhesive zone canextend from adjacent the mouth toward the bottom wall segment along atleast a majority of the height of the opposing wall segments. Theadhesive zones can have a greater affinity for adhesion to each otherthan to the items and permit the package to be reclosed using theadhesive zones at a plurality of different heights of the opposing wallsegments. Reclosing the package at the plurality of different heightscan allow the head space in the package above the items to be minimizedas the items are sequentially removed from the package at discretetimes.

In another aspect, the package can include at least two walls havingfacing inner surfaces, where the at least two walls are sealed to eachother along longitudinal edge portions thereof to form a tubularpre-package. The tubular pre-package is initially sealed on top andbottom edge portions thereof, forming an initially sealed package havingan interior cavity storing the items. The package can further include alow tack adhesive disposed in a pattern substantially spanning thecircumference of the tubular package on aligned portions of the facinginner surfaces of the at least two walls. Preferably, the pattern isdisposed intermediate of the top and bottom edge portions. Further, thelow tack adhesive has a greater affinity for adhesion to itself than tothe items, which effectively permits the package to be reclosed adjacentto the items after the items are sequentially removed by pressure of thelow tack adhesive disposed on the facing inner surfaces together.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a reclosable package showing the mouthin its initial, closed configuration and the items at a filled level;

FIG. 2 is a cross-sectional side elevational view of the reclosablepackage of FIG. 1 taken along line 2-2 in FIG. 1 and showing the itemsat the filled level;

FIG. 2A is an enlarged portion of the cross-sectional side elevationview of FIG. 2 showing layers of the film wall of the reclosablepackage;

FIG. 3 is a perspective view of the reclosable package of FIG. 1 showingthe mouth in an open configuration with the items at the filled level,and showing a partial sectional view of a portion of the package;

FIG. 4 is a perspective view of the reclosable package of FIG. 1following initial opening of the mouth and removal of some of the itemstherethrough, and showing the items at an intermediate level and sealedopposing walls above the items;

FIG. 5 is a cross-sectional view of the reclosable package of FIG. 4showing the items at the intermediate level and the sealed opposingwalls above the items;

FIG. 6 is a perspective view of the reclosable package of FIG. 1following initial opening of the mouth and removal of even more of theitems therethrough, and showing the items at a low level and the sealedopposing walls above the items;

FIG. 7 is a cross-sectional view of the reclosable package of FIG. 6showing the items at the low level and the sealed opposing walls abovethe items;

FIG. 8 is a perspective view of the reclosable package of FIG. 1 showinga removed portion above the sealed opposing walls above the items at theintermediate level;

FIG. 9 is a top plan view of a single web of flexible material showing apattern of low tack adhesive; and

FIG. 10 is a top plan view of a single web of flexible materials showinga pattern of low tack adhesive.

DETAILED DESCRIPTION

A reclosable package 10 is provided to allow a user to reclose thepackage 10, while also reducing headspace above items 12 stored insideof the package 10 while the items 12 are sequentially removed from thereclosable package 10. The items 12 can be any product suitable for thepackage 10, such as a food product, including, without limitation,crackers, cookies, cheese, meat, coffee, nuts, dried fruits, spices,etc., or other products that are sequentially removed, such as compactsdiscs, batteries, or office supplies, to name a few. In the exemplaryembodiment described herein, the items are described with regard to afoodstuff.

The reclosable package described herein is achieved at least in partthrough the use of a low tack adhesive 14 disposed on opposing innersurfaces 16 of the reclosable package 10, where the low tack adhesive 14has a greater affinity for adhesion to itself than to the foodstuff 12.This allows the low tack adhesive 14 on the opposing inner surfaces 16to be sealed together, such as by a user pressing the opposing innersurfaces 16 together, even when the foodstuff 12 has come into contactwith the low tack adhesive 14 during removal of the foodstuff 12. Thereclosable package 10 can optionally include an area of weakness 18disposed around a perimeter of the reclosable package 10 to allow a userto remove a portion of the reclosable package 10 above the foodstuff 12and adjacent a sealed area of the opposing inner surfaces 16, therebydecreasing the size of the package 10.

In one aspect, the low tack adhesive 14 and package 10 are generallyconstructed or have a composition to minimize the adhesion of theadhesive 14 to undesired surfaces or foodstuffs 12 and still function atthe same time as an effective reclosable fastener. That is, the adhesive14 has a unique formulation or construction to achieve select tack andpeel values so that the adhesive-based fastener can be opened and closedmultiple times to seal the contents in the package 10 during use by aconsumer, but at the same time not delaminate from the film substrateforming the opposing inner surfaces 16.

To this end, the adhesive 14 generally includes a UV-cured adhesive withrelatively low tack levels to minimize adhesion to the unwantedsurfaces, a selected bonding or opening peel strength sufficient toenable secure reclosure of the package 10, and a peel strength robustenough to enable repeated opening and reclosing of the package 10. Atthe same time, the adhesive 14 also has a strong bond to the filmsubstrate so that the adhesive 14 does not delaminate upon opening ofthe package 10. By one approach, the adhesive 14 may include specificblends of a UV-curable acrylic oligomer and a tack control agent. Inother approaches, the adhesive 14 may include specific blends of theUV-curable acrylic oligomer, the tack control agent, and an elastomer(rubber) component.

Preferably, the adhesive 14 is a UV-cured pressure sensitive adhesive(PSA) exhibiting cohesive properties and low tack, but, despite the lowtack, still forms a strong bond to the film substrate forming theopposing inner surfaces 16. As generally understood, a cohesive-basedmaterial typically adheres more readily to like materials (i.e.,self-adhesion) rather than to non-like materials. Suitable adhesivematerials used herein generally exhibit a relatively low tack toundesired surfaces, but at the same time still exhibit a good bondstrength to desired surfaces (such as no delaminating from the flexiblefront and back panels), and relatively good cohesive or self adhesionbond strength to like surfaces to hold a flexible package or pouchclosed, but still permit the package to be openable or peelable by hand.The selected adhesive-based materials also permit debonding or peelingfrom such like materials so that the adhesive layers may be repeatedlypeeled apart without substantial damage to the adhesive material and/orany underlying substrate. When the adhesive material is debonded orpeeled apart, the selected adhesive materials has sufficient internalintegrity and generally peels apart at an adhesive bonding interfacesubstantially cleanly without substantial material picking, stringiness,delamination from the substrate, and/or other substantial disfigurationsof the material (i.e., globbing, pilling, etc.). Advantageously, theadhesive-based fasteners herein maintain a peel adhesion where opposingadhesive strips contact each other with an average initial peel adhesiongreater than about 200 grams per linear inch (gpli) and, preferably,between about 200 and about 900 gpli. Moreover, in some instances, theadhesive-based fasteners 14 retain greater than about 200 gpli and/or atleast about 30 to about 200% of the average initial peel adhesion afterfive repeated seal and unseal operations.

In another aspect, the package 10 and adhesive 14 are also constructedto interact with each other so that the bond or peel strength of theadhesive 14 to the inner substrate surface 16 is generally greater thanthe opening peel strength between the layers of the adhesive 14 itself.In this manner, the adhesive 14 generally remains adhered to the innersurfaces 16 and does not substantially pick, string, or delaminate fromthe inner surfaces 16 when the package 10 is opened by a consumer as theadhesive 14 is peeled open. For example and in one approach, the bond orpeel strength of the adhesive to the package film substrate is greaterthan about 900 gpli and is capable of withstanding multiple peel andre-seal cycles without detachment from the film substrate. In addition,the adhesive is cured so that it is capable of withstanding more than100 double rubs with methyl ethyl ketone (MEK) solvent (ASTM D5402-06).

Referring now to FIGS. 1-10, an exemplary form of the reclosable package10 is constructed from a single web 20 of flexible material top andbottom edge portions 22, 24, 42, and 44 and side edge portions 26.Before the web 20 is formed into the package 10, the low tack adhesive14 may be applied or printed in a pattern 28 on a surface 29 of the webforming inner surfaces of the package 10. The low tack adhesive 14 mayinstead be formed on the web 20 at the time the package 10 is formed.The pattern 28 can take any suitable shape, including, for example allof the web 20, substantially all of the web 20 except for hermetic sealportions and tolerances therearound, on a majority of the web 20, suchas intermediate of the top and bottom of the web 20 as shown in FIG. 9,or strips spaced along a height of the web 20 as shown in FIG. 10. Thepattern 28, however, preferably at least substantially spans between theside edges 26 at desired heights, allowing for a longitudinal sealportion, so that the adhesive 14, when the package 10 is formed, canform a continuous seal.

In the illustrated form, the web 20 can be used to form the reclosablepackage 10, such as a typical vertical or horizontal form, fill, andseal type of pouch. In this form, the package 10 has a tubular shapesealed longitudinally by a fin seal 30 between the side edge portions 26of the web 20. The package 10 includes a front wall 32 and a rear wall34, each having top and bottom edge portions 36, 38 thereof. The package10 further includes side walls 40 connecting the front and rear walls32, 34 and having top and bottom edge portions 42, 44. In theillustrated form, a bottom seal 46 is formed between the bottom edgeportions 38 of the front and rear walls 32, 34 and between the bottomedge portions 38 of the front and rear walls 32, 34 and the bottom edgeportions 44 of the side walls 40. As illustrated, the side walls 40 foldinwardly at the bottom edge portions 44 to form the bottom seal 46,however, the side walls 40 could also fold outwardly to form anoutwardly extending bottom seal. Folding the bottom edge portions 44 ofthe side walls 40 inward can create a bottom segment 48 for the package10, upon which the package 10 can rest in a vertical orientation. In ananother form, two webs with a mirrored pattern of low tack adhesivecould be utilized where the webs are sealed together on opposing edgeportions to create the tubular form. In yet another form, a gusset canbe made along the bottom or sides of the package.

With the creation of the bottom seal 26, an interior cavity 50 is formedwithin the package 10 having a mouth 52 formed by the top edge portions36, 42 of the front, rear, and side walls 32, 34, and 40. As in thetypical form, fill, and seal process, after the longitudinal fin seal 30and the bottom seal 46 are formed, the cavity 50 can then be filled withthe foodstuff 12. As with the bottom seal 46, a top seal 54 can beformed between the top edge portions 36 of the front and rear walls 32,34 and between the top edge portions 42 of the side walls 40. In theillustrated form, the top seal 54 is spaced from a top edge 53 of thepackage 10. This spacing creates a flange 55 which provides a grip for auser when opening the package 10, such as by breaking or removing thetop seal 54. In this aspect, either one or both of the top seal 54 andthe bottom seal 46 can be removable, meaning, for example, that the topseal 54 and the bottom seal 46 can be initially broken, or the entireseal 46, 54 can be removed from the package 10, such as with the aid ofan area of weakness. So configured, the package 10 can be filled withthe foodstuff 12 and hermetically sealed for storage, shipping, anddisplay. The package 10 can then be opened by removing one of the seals46, 54, the foodstuff 12 removed, and the package 10 resealed by sealingthe opposing inner surfaces 16 together using the low tack adhesive 14.

As discussed previously, the package 10 can be provided to the user withthe interior cavity 50 in an initially hermetically sealed conditionenclosed by the bottom seal 46, the top seal 54, and the fin seal 30storing the foodstuff 12. The user can then break or remove the top seal54 to access the interior cavity 50 and the foodstuff 12. Following theinitial breaking or opening, as the user sequentially removes thefoodstuff 12 from the interior cavity 50, an increasing amount ofheadspace is created above the foodstuff 12. The low tack adhesive 14can be utilized by the user to sequentially reduce this headspace.

As provided herein, the package 10 is reclosable at heights of thepackage 10 intermediate of the top seal 54 and the bottom wall segment48, and specifically at heights where the pattern 28 of the low tackadhesive 14 substantially extends around a circumference of the package10. As illustrated, the pattern 28 of the low tack adhesive 14 can covera majority of the web 20, such as an area offset toward an upper portionof the package 10 as shown in FIG. 9, or all the web 20 except for thetop and bottom edge portions 22, 24 and the side edge portions 26.Alternatively, the pattern 28 of the low tack adhesive 14 can becomposed of a plurality of transversely disposed strips of low tackadhesive 14, such as those shown in FIG. 10. Accordingly, when a portionof the foodstuff 12 is removed, creating headspace in the package 10,the user can fold the side walls 40 inwardly at a height adjacent thefoodstuff 12 and where the pattern 28 of the low tack adhesive 14 isdisposed. After the side walls 40 have been folded inward, the user canpress the front and rear walls 32, 34 together, pressing thecircumferentially disposed low tack adhesive 14 together. As previouslydiscussed, due to the low tack adhesive 14 having greater affinity foradhering to itself than to the foodstuff 12, the pressure applied by theuser adheres the low tack adhesive 14 together and effectively reclosesthe package 10. The package 10 can then be reopened by breaking the sealbetween the low tack adhesive 14 disposed on the front, rear, and sidewalls 32, 34, 40, providing access to the foodstuff 12. As sequentiallymore foodstuff 12 is removed, the user can reclose the package 10adjacent the foodstuff 12 to remove additional headspace in the package10 by applying pressure against the low tack adhesive 14 at any of aplurality of heights as designed by the user within a zone where thereis low tack adhesive 14 on the opposing walls. The zone may extend theentirety of the original interior height of the package 10, or may be atselect heights only, e.g., the lower third, the upper third, the uppermajority, the upper two-thirds or the upper three-quarters. Furthermore,a plurality of spaced zones can be provided, such as in fractions of25%, 20% or 10%, and optionally can include exterior indicia on thepackage as to where the zones are located, such as graphics, areas ofweakness or the like.

In one form, the web 20 may be formed of several layers of flexiblematerials. As illustrated, the web 20 includes an interior layer 56, anintermediate layer 58, and an outer layer 60. In one example, theinterior layer 56 is a coextruded film with a heat sealablefunctionality, made substantially of a heat-sealable polymer compositionsuch as polyethylene, EVA, Surlyn or blends thereof; the intermediatelayer 58 is a metallic foil material, such as aluminum; and the outerlayer 60 may be PET, such as an oriented PET. So configured,advertisements or other alphanumeric or graphical content can bedisplayed on the outer layer 60, such as by printing or adhering alabel. The combination of the layers 57, 58, 60 acts as a barrier to theinterior cavity 50.

Preferably, the adhesive is UV-cured, and more preferably a UV-cured PSAadhesive exhibiting cohesive properties and low tack, but forms a strongbond to the film substrate forming the walls 32, 34, 40 of the package10. As generally understood, a cohesive-based material typically adheresmore readily to like materials (i.e., self-adhesion) rather than tonon-like materials. Suitable cohesive materials used herein generallyexhibit a relatively low tack to undesired surfaces, a good bondstrength to desired surfaces (such as no delaminating from the flexiblefront and back panels), and relatively good cohesive or self adhesionbond strength to like surfaces to hold a flexible package or pouchclosed, but still openable or peelable by hand. The selectedcohesive-based materials also permit debonding or peeling from such likematerials so that the cohesive layers may be repeatedly peeled apartwithout substantial damage to the cohesive material and/or anyunderlying substrate. When the cohesive material is debonded or peeledapart, the selected cohesive materials has sufficient internal integrityand generally peels apart at a cohesive bonding interface substantiallycleanly without substantial material picking, stringiness, delaminationfrom the substrate, and/or other substantial disfigurations of thematerial (i.e., globbing, pilling, etc.).

The first component of the adhesive is one or more UV-curable acrylateor acrylic oligomers. For instance, the UV-curable acrylic oligomer maybe an acrylic or methacrylic acid ester having multiple reactive orfunctional groups (i.e., acrylic or methacrylic oligomers). In general,a functional group includes one UV reactive site. UV reactive sites aremost commonly carbon-carbon double bonds conjugated to anotherunsaturated site such as an ester carbonyl group. By one approach, theUV-curable acrylic oligomer is an acrylic or methacrylic acid ester of amultifunctional alcohol, which means the oligomer has more than oneacrylated or methacrylated hydroxyl group on a hydrocarbon backbone ofthe oligomer. By one approach, the adhesive may include about 1 to about90% by weight of the UV-curable acrylic oligomers and withfunctionalities of about 1.2 to about 6.0. In another approach, theUV-curable acrylic oligomers may have a functionality of about 2.0 toabout 3.0, and/or be provided in the adhesive in an amount of about 20to about 70% by weight.

In one form, the multifunctional UV-curable acrylic acid ester is anacrylic acid ester of a vegetable oil having a reactive functionality of2.0 or greater. In another aspect, the UV-curable acrylic oligomer cancomprise an epoxidized soybean oil acrylate. In general, the amount ofthe UV-curable acrylic oligomers used, based on a preferred adhesivecomponent ratio (ACR) (to be discussed herein), can impact theproperties of the final adhesive. For instance, where the amount of theUV-curable acrylic oligomer is too low, based on the preferred ACR, thecure rate of the final adhesive is too slow. On the other hand, wherethe amount of the UV-curable acrylic oligomer is too high, based on thepreferred ACR, the final adhesive may be adequately cured but can haveinadequate self adhesion properties to seal and reseal.

The second component of the adhesive is a tack control agent. By oneapproach, the adhesive may include about 1 to about 65% by weight of thetack control agent. In another approach, the tack control agent can bepresent in amounts from about 20 to about 65%. The tack control agentcan include a tackifying resin or a curable polymer/monomer combinationthat when cured can produce the desired levels of tack and self-adheringproperties appropriate for the reclosable fastener. In one aspect, thetack control agent can comprise an aliphatic urethane acrylatedoligomer. Many other types of tack control agents suitable forUV-curable PSA adhesives may also be used in the reclosable adhesivesystem.

An optional third component of the adhesive is an elastomeric or rubbercomponent. By one approach, the elastomeric component may include atleast one curable acrylated (i.e., acrylic modified) or methacrylatedesters of a hydroxy-terminated elastomeric polymer (i.e., an elastomericpolyol). This elastomeric component can include acrylic-modifiedpolybutadiene, a saturated polybutadiene and/or a flexible polyurethane.In one aspect, a methacrylated polybutadiene can be provided. Theelastomeric material can be provided in amounts of about 0 to about 20%when used in the adhesive. In one aspect, the elastomeric material isprovided in amounts of about 5 to about 15%. Satisfactory adhesives canbe made with the desired low tack, resealable properties as describedherein without the elastomer component; however, it is believed that theelastomeric component aids in achieving an optimal coating performance.The optimal adhesive performance can be defined by properties such asself-adhesion, tack, viscosity, and cure rate, just to name a few. Theelastomeric component is useful for adjusting peel strength properties,substrate adhesion strength, increasing flexibility, viscosity control,and cure rate modulation.

The average initial peel strength of a properly cured adhesive can be inthe range of about 200 gpli to about 900 gpli and, in particular, about280 gpli to about 800 gpli, as measured by ASTM D3330/D3330M -04 methodF. The adhesive is also designed to retain its average peel afterrepeated open and close operations (i.e., adhesion retention).Preferably, the cured adhesive can retain its average initial peeladhesion between about 280 and about 800 gpli up to at least fiverepeated peel-reseal cycles. Preferably, the adhesion retention valueupon peeling-resealing-peeling can be between about 30 to about 200%retention of the initial value. Upon contaminating the adhesive withcrackers, the adhesion retention value can be between about 30% to about150% of the initial value, where the cracker contamination test methodis as described herein.

In another form, the package 10 can further include one or more areas ofweakness 18 spanning between the side edge portions 26 of the web 20. Asillustrated, there are a plurality of areas of weakness 18 disposedwithin a span of the height of the package 10, such as offset from thelongitudinal center of the package toward the top of the package 10.Alternatively, any number of areas of weakness 18 can be utilized,longitudinally spaced from one another when more than one, whereverseparation of the package 10 is desired. Additionally, the one or moreareas of weakness 18 can be disposed generally transversely across thepackage 10 or can be disposed at an angle or contain other combinationsof linear or curvilinear segments as the area of weakness 18 spans thewidth of the package. The areas of weakness 18, so disposed, may beseparated by the user as the foodstuff 12 is sequentially removed fromthe package 10 in order to reduce excess material above the foodstuff 12and allow for easier access to the remaining foodstuff 12 and easierevacuation of the foodstuff 12. Graphics or other indicia on theexterior of the package may coincide with the one or more areas ofweakness.

Because portions of the areas of weakness 18 are disposed on a portionof the package 10 that covers the hermetically sealed interior cavity46, the areas of weakness 18 preferably only score the web 20, such asthrough the outer layer 60, the interior layer 56, or a combination ofthe outer or interior layer 60, 56 and the intermediate layer 58. In theillustrated form, the area of weakness 18 includes a series of smallscores (laser or mechanical), however, other patterns, shapes, and sizesof scores, perforations, thinned die lines and the like can be utilized.

In the exemplary embodiments illustrated herein, the reclosable package10 has a generally rectangular cross-section having four sides. In use,however, the package may take any suitable shape of sufficientlyflexible material, including, for example, curvilinear shapes, such asgenerally circular or elliptical, or shapes with linear cross-sectionalsides, such as a triangle, a quadrilateral, a hexagon, an octagon, orother regular or irregular polygons. Such shapes can be utilized with apartially flexible material that allows the sides of the reclosablepackage 10 to be pressed together. Further, the sides may be connectedby fold lines or seals. Thus, the sides may not be discrete from eachother, e.g., comprising separate webs of film, but rather may generallyhave the appearance of having multiple sides or walls.

As discussed herein, the package 10 has been described for use with thefoodstuff 12. The foodstuff 12 may include any suitable food material,including solids, liquids, or combinations thereof. Additionally, thepackage 10 may be utilized to store other materials, such as anysuitable plastic, metal, organic material, or combinations thereof.

Advantages and embodiments of the adhesive described herein are furtherillustrated by the following examples; however, the particularconditions, processing schemes, materials, and amounts thereof recitedin these examples, as well as other conditions and details, should notbe construed to unduly limit this method. All percentages are by weightunless otherwise indicated.

EXAMPLES Example 1

Various blends of acrylic oligomers, tack control agents and elastomericmaterials were tested for compatibility and storage stability (stabilitybeing defined as a mixture that does not form gels or visibly separateafter storing for up to 3 days at room temperature). Table 1 below showsthe combinations tested and the formulation levels used.

TABLE 1 Adhesive Formulations Tested for Stability % Component Providedin Final Adhesive Formulation Adhesive Component Storage StabilityAcrylic Tack Tack Tack Ratio of Liquid Blend Oligomer Elastomer AgentElastomer Agent Agent (ACR) Observation after Sample No. A B C D E F — 3days 1 40 15 45 — — — 0.67 Stable, no visible (Inventive) gels, no phaseseparation 2 — 15 45 — 40 — 0 Stable - but did (Comparative) not curebecause too low ACR 3 40 — 45 15 — — 0.67 Unstable, because(Comparative) phases separated; components were incompatible 4 — — 45 1540 — 0 Unstable, because (Comparative) phases separated and ACR too low5 40 15 25 — — 20 0.67 Stable, no visible (Inventive) gels, no phaseseparation 6 40 15 — — — 45 0.67 Unstable, because (Comparative) phasesseparated; components were incompatible 7 60 — — — — 40 1.5 Unstable,because (Comparative) phases separated 8 — — — — 60 40 0 Unstable,gel-like (Comparative) structure formed and ACR too lowThe components are identified as follows:

-   A=acrylated epoxidized soybean oil (CN 111 US, Sartomer Company,    Exton, Pa.).-   B=methacrylated polybutadiene (Ricacryl® 3500, Sartomer Company).-   C=tackified aliphatic acrylate oligomer (CN 3001, Sartomer Company).    This component comprises a blend of an aliphatic urethane acrylate    and hydrocarbon tackifier resins.-   D=polybutadiene styrene copolymer (Ricon 184, Sartomer Company).-   E=tackified aliphatic urethane acrylate oligomer (CN 3211, Sartomer    Company).-   F=tackifier concentrate made with a light colored, low odor aromatic    resin (PRO 11236, Sartomer Company).

${{Adhesive}\mspace{14mu} {Ratio}\mspace{14mu} ({ACR})} = \frac{( {{wt}\mspace{14mu} \% \mspace{14mu} {Acrylic}\mspace{14mu} {Oligomer}} )}{( {{{wt}\mspace{14mu} \% \mspace{14mu} {Elastomer}} + {{wt}\mspace{14mu} \% \mspace{14mu} {Tackifier}}} )}$

Stability or compatibility of these adhesive components may be a factorfor manufacture, shipping, in-plant storage, and use of the liquidcoating mixture. The stability was judged visually by appearance andconsistency of the observed formulation after storage over a period of 3days (about 72 hours). It was observed that Samples 1, 2 and 5 in Table1 provided visually satisfactory blends of the various adhesivecomponents that after 3 days remained homogeneous, i.e., the componentsdid not visibly separate or form gels. Although Sample 2 resulted in astable formulation, this adhesive component had an undesired ACR and didnot cure well (i.e., this can be seen from the MEK Rub Cure test inTable 3 below, for similarly formulated Sample 10). However, Samples 1and 5 provided stable adhesive blends that cured well and also had adesired ACR in the range of 0.5 to 1.5. The other sample blends eitherseparated, became too viscous and/or gelled (i.e., Sample 8 becamegel-like after 3 days). Sample 8 formed a gel, which indicated that thecomposition formed by the aliphatic acrylate, or component E, combinedwith the tackifier component F was not compatible.

Thus, to achieve a stable adhesive that is appropriate for use asdisclosed herein, the stable adhesive generally needs to have one of thefollowing and, in some cases, more than one of the following, and inother cases, all of the following factors: compatible components,curable, desired ACR, and all three component parts present (i.e.,acrylic oligomer, elastomer, and a tack control agent).

Example 2

Based on the initial adhesive compatibility results for the stableformulations from Example 1, these formulations were further refined toproduce five formulations of adhesive coatings that were all stable forat least 24 hours as a blend of the components indicated in Table 2.

TABLE 2 Revised Adhesive Formulations % Component Provided in FinalAdhesive Formulation Adhesive Stability Acrylic Tack Tack Tack Componentafter 24 Sample Oligomer Elastomer Agent Elastomer Agent Agent Ratio(ACR) hours No. A B C D E F — — 9 40 15 45 — — — 0.67 Yes 10 — 15 45 —40 — 0 Yes 11 40 15 20 — — 25 0.67 Yes 12 50 — 45  5 — — 1 Yes 13 45 —45 10 — — 0.82 Yes

The components A through F are as indicated above in Example 1. Samples9 and 10 correlate to Samples 1 and 2, respectively, from Example 1.Sample 11 is a variation of Sample 5 from Example 1. The remainingsample formulations were new.

After the five adhesive formulations exhibited good compatibility for atleast one day, the five samples were all combined with about 1% of aphotoinitiator (Esacure® KTO 46, Lamberti Spa, Italy) and then testedfurther. The photoinitiator was comprised of a liquid mixture oftrimethylbenzoyldiphenyl phosphine oxide, α-hydroxyketones andbenzophenone derivatives. The samples were then coated onto filmsubstrates comprising ethylene vinyl acetate copolymer (EVA),Metallocene low linear density polyethylene (LLDPE) and about 12 percentof an organoclay composition (about 57-63% organically modified clay andmaleic anhydride grafted linear low density polyethylene carrier,PolyOne Corporation, McHenry, Ill.). In particular, the substrate hadabout 77 wt % (EVA), about 10 wt % Metallocene LLDPE, and about 13 wt %organoclay composition. The samples were then cured after being coatedonto the film substrates, where the curing was effected by applicationof UV radiation with three passes under a “D” bulb, which is a mercurywith iron halide bulb. A single pass under a D bulb was approximatelyequivalent to 75 mJ/cm2 to 100 mJ/cm2. After the coating was cured, thecured adhesive layer was evaluated for the degree of cure andeffectiveness to bond to the film.

The degree of cure of the adhesive was tested using a solvent rubresistance test referred to as a methyl ethyl ketone (MEK) rub test, asper ASTM D5204. Good cure results were shown by an MEK rub value of 100double rubs or more, which indicated that the adhesive was cured welland thus showed a resistance to the MEK rubbed over it. Poorly curedadhesives did not show much resistance to the MEK (e.g., 10 double rubsor less). MEK rub test results can be seen in Table 3 below.

Tack and initial peel of the adhesives were also observed, and reportedsubjectively. The tackiness of the adhesive layer was observed upontouching and the level of tack was evaluated on a scale of Low (L),Medium (M), and High (H). Similarly, the subjective force required topeel apart the samples by hand was also evaluated on a scale of L, M,and H. These test results can be seen in Table 3.

TABLE 3 Test Results for Cure and Preliminary Adhesion for Table 2Formulations. MEK Rub Test Subjective Subjective Sample No. (# of doublerubs) Tack Test Peel Test  9 >100 M M (Inventive) 10  ~10 M-H M-H(Comparative) 11 >100 M M (Inventive) 12  100 M M (Comparative) (Haze onsurface) 13  100 M-H M-H (Comparative) (Haze on surface)

All of the samples had at least moderate tackiness and peel strength.Sample 10 had the highest subjective tack and peel but the poorest cure,as evidenced by an MEK rub test of about 10, which showed that afterabout 10 rubs of MEK the adhesive was removed from the substrate.Samples 12 and 13 had a haziness upon performing the MEK rub test, mostlikely due to component D, the polybutadiene styrene copolymer, risingto the surface when rubbed with MEK. Therefore, although Samples 12 and13 fall within the desired adhesive ratio range, component D does notappear to be compatible with the other two components and thus is not asatisfactory adhesive compound. It was desirable to find an adhesivewith a subjective tack result of medium or lower, subjective peel forceof medium or higher and an MEK rub test of 100 double rubs or greaterwithout haze formation, which at a minimum, Samples 9 and 11 exhibited.

Example 3

The curing effectiveness of three different variations of an adhesiveformulation were tested by applying the adhesive to the same filmsubstrate as described in Example 2 and then curing in three differentmanners; a UV-curing step (“UV Cure”) performed on commercial equipment,an electron beam (EB) curing step (“EB Cure”) performed on a similarcommercial system as the UV-cure but utilizing electron beam technology,and an EB cure performed on laboratory equipment (“EB Lab Cure”). Table4 below shows the formulation of the three adhesives tested. Thecommercial EB system and lab EB system are both compared due to thevarying energy levels supplied by each. The acrylic oligomer is CN 111US, the elastomer is Ricacryl® 3500 and the tackifier is CN 3001 asdescribed in Example 1.

TABLE 4 Sample Adhesive Formulation % Provided in Final AdhesiveFormulation Adhesive Acrylic Tack Component Ratio Sample No. OligomerElastomer Agent (ACR) 14 69.2 7.7 23.1 2.2 (Comparative) 15 45 15 400.81 (Inventive) 16 35 15 50 0.53 (Inventive)

The “UV Cure” comprised passing the coated sample under a UV-lamp atabout 25 ft/min in air and with about 2 to 4 passes, such that thesample was passed under the length of the UV-lamps 2 to 4 times. Theenergy provided by 1-pass of the UV lamp at 25 ft/min was equivalent toabout 100 mJ/cm2. The “EB Cure” on a commercial system (FaustelCorporation, Germantown, Wis.) was performed under nitrogen gas at about125 ft/min to about 250 ft/min with only one pass and at about 2 Mrad toabout 2.4 Mrad, and the “EB Lab Cure” was also performed under nitrogenrequiring about 6 to 8 passes under the lab EB system, which operated atabout 10 ft/min. Total cumulative dose for 6-8 passes through the lab EBunit was about 2 Mrad to about 4 Mrad. It is appreciated that a smoothsurface finish of the adhesive fastener 12 is desired in some cases fora good adhesive to adhesive peel strength. If the surface of theadhesives 12 is lumpy, such as having a consistency of an orange peel,the adhesive fasteners 12 tend not to adhere together well. It wasobserved that all cured coating samples had comparably smooth and levelsurface finishes. After curing all of the samples, the peel strengthswere tested per ASTM D3330/D3330M-04 method F, these results are shownin Table 5 below.

TABLE 5 Peel Strength Results for Different Cure Processes (UV vs.E-beam) Peel Strength Results Inventive Comparative Peel Peel PeelStrength Strength Strength under UV under EB Under EB Cure No. UV CureNo. EB Lab Cure No. EB Sample No. Condition Passes Condition PassesConditions Lab Passes 14 200 gpli 2 0 gpli 1 100 gpli 6-8 passes(Comparative) 15 480 gpli 3.5 0 gpli 1 200 gpli 6-8 passes (Inventive)16 680 gpli 4 0 gpli 1 200 gpli 6-8 passes (Inventive)

Surprisingly, it was found that an ultraviolet curing treatment (UVCure) outperformed both of the EB cures. The EB Cure performed on thecommercial line had no adhesion at all, i.e., peel strength of 0 gpli.The EB Lab Cure had some adhesion, but the UV-cured samples had the bestadhesion overall.

In terms of the UV Cure results, Samples 15 and 16 had acceptable rangesof peel strengths (i.e., 480 gpli and 680 gpli, respectively) whereasSample 14 had a lower peel strength (i.e., 200 gpli). The lower peelstrength seen in Sample 14 is likely due to the adhesive formulationused with Sample 14, which did not fall within the desired range of 0.5to 1.5 (i.e., it had a ratio of 2.2).

While not wishing to be limited by theory, it is believed that aUV-radiation cure in ambient air (about 21% oxygen) provides a cure fromthe bottom of the sample up toward its surface due to the oxygeninhibition of free radical curing in adhesive portions adjacent or nearthe surface. The tacky components are more aliphatic in nature andtherefore are lower in surface energy than, for example, the ester orurethane components. In some cases, chemical systems self-organize tothe lowest possible energy state if allowed sufficient time. In thepresent case, it is believed that the slower cure rate of the UV processallows sufficient time for the tacky components of the coating tomigrate toward the surface. In contrast, the EB curing process resultsin a much faster reaction cure rate, thus providing a more randomarrangement of the polymer where it sets up cross-links within thegrowing polymer network too quickly for significant surface-energydriven self-ordering to develop. Thus, the EB cure may have an oppositecure pattern than the UV-radiation process, where EB curing commonlytakes place in a nitrogen-purged environment and may cure faster at thesurface and slower near the substrate. This can result in a completelydifferent adhesive behavior based solely on the different cure methods.Ordinarily, such a rapid cure would be desirable, however, when curingthe coating disclosed herein, such a fast cure is a disadvantage becauseit does not allow sufficient time to transpire in the process for theadhesive components to become fully organized.

While not wishing to be limited by theory, it is further believed thatthe slower cure time of the UV radiation curing allows for the growingpolymer units to arrange themselves, such that polar units of thepolymer favor the substrate and non-polar units favor the surface, wherehaving the non-polar units near the surface of the substrate allows theadhesive coating to bond and stick to itself. This allows the adhesivecomponents that are most compatible with the film substrate tocongregate at the adhesive/substrate interface, thus enhancing thesubstrate adhesion, which may be one factor that aids in the absence ofdelamination from the substrate film.

Example 4

Two inventive adhesive-based reclosable fasteners, Samples 17 and 18,were prepared as indicated in Table 6. The two sample adhesives werecompared to a standard pressure sensitive adhesive fastener(PSA-control, Sample 19) obtained from a commercial Nabisco Chips AhoySnack'n Seal® package using a standard PSA (Fasson 5700, Avery DennisonCorp., Pasadena, Calif.).

TABLE 6 Adhesive-based Fastener Formulations % Component Provided inFinal Adhesive Formulation CN 111 US Esacure ® Adhesive (AcrylicRicacryl ® 3500 CN 3211 KTO46 Component Samples Oligomer) (Elastomer)(Tack Agent) (Photoinitiator) Ratio (ACR) 17 35 12 50 3 0.56 (Inventive)18 35 0 62 3 0.56 (Inventive)

The substrate that was coated comprised about 77.2% EVA, about 10%metallocene LLDPE, and about 12.8% organoclay filler composition PolyOne231-615 masterbatch. The masterbatch comprises about 57% to about 63%organically modified clay and a carrier that contains MA-LLDPE andpolyethylene. Sample 17 was cured at a UV-curing station having anaverage light energy of about 730 mJ/cm2 and an average line speed ofabout 100 ft/min at an average oven temperature of 130° F. Sample 18 wascured at the UV-curing station having a light energy of about 700 mJ/cm2with a line speed of about 100 ft/min at an oven temperature of 160° F.The standard adhesive, PSA-control, was already provided in a final formadhered to a cookie package (Kraft Foods).

A crumb contamination test was performed on all three packages to see ifthe food particles would negatively impact the sealing of its respectiveadhesive. The crumb test procedure comprised the following steps: first,Triscuit® crackers were obtained and crushed using a bottom of a glassjar. The breaking of the crackers in this fashion created smallparticles that would be consistent with what would be found in thebottom of a bag. Next, a 2 inch diameter ring fixture was placed ontothe adhesive of the sample to be tested. Approximately 5 grams of crumbswere placed into the ring on the sample. The sample and ring were gentlyagitated back and forth to settle the crumbs onto the adhesive surfaceof the reclosable fastener. The ring was removed from the sample and thecrumbs were gently shaken off of the sample and disposed. The ring wasreplaced back on the substrate in its original position and the areaexposed to the crumbs was visually rated for the quantity of crumbsretained. A visual rating scale of zero to 100 was used, where zeromeant no visible retained crumbs and 100 meant the total surface wascovered with adhering crumbs. The results of the cracker crumb test areshown in Table 7.

Additionally, the peel strength of the adhesives was tested aftercontaminating with cracker crumbs. The peel strength was measured usinga standard testing procedure, ASTM D3330/D3330M-04 method F, where thestrength of the adhesive bond was tested by peeling one side away fromthe other and measuring the peel strength that was required. An initialpeel strength, a subsequent peel strength after an initial contaminationwith cracker crumbs, and a second peel strength after a second round ofcontamination with cracker crumbs, where the sample was contaminatedusing the same procedure as the initial contamination, were measured.The results for the samples are presented in Table 7.

TABLE 7 Crumb Contamination Test Results Initial peel Peel strength Peelstrength % Peel strength strength (no after first % Peel strength aftersecond retained after contamination) contamination retained after firstcontamination second Contamination Samples (gpli) (gpli) contamination(gpli) contamination rating 17 315 167 53% 128 41% 0-10 18 116 161 138%155 133% 0-10 19 499 196 39% 25 5% 60-80  (PSA- Control)

It can be seen from the results that the adhesivity (i.e., peelstrength) of the PSA-control, as measured per ASTM test D3330/D3330M-04method F, dropped to about 5% of its initial peel force value (i.e.,from about 500 gpli to about 25 gpli) after only two cracker crumbexposures. In contrast, both of the adhesive-based Samples 17 and 18retained at least about 41% of its initial peel force value after twoexposures to the cracker crumbs, with Sample 18 actually showing anincrease in peel force after contamination and after repeated closuresand openings. Additionally, the visual crumb contamination ratings forthe adhesive-based samples were 0 to 10, compared to values of 60 to 80for the PSA-control.

A rolling ball tack test was also performed on uncontaminated Samples17, 18, and 19, which was a modified version of ASTM D3121 and followedthe test method parameters of ASTM D3121, unless otherwise specified.The modified test measured how strong the surface of the coating adheredto non-like materials, such as the polar surface of a rolling glassball.

The rolling ball method included: releasing a glass ball which wasplaced two inches up the standard incline specified in the ASTM methodand allowing the ball to accelerate down the incline and roll across ahorizontal surface of the pressure sensitive adhesive sample. Themodified test version included using a glass ball instead of a metalball, the glass ball having a diameter of about ⅛ inch, and using ashortened release point off of the incline (i.e., as indicated above,two inches up the incline). The relative tack was determined bymeasuring the distance the ball traveled across the adhesive beforestopping, beginning from the end of the ramp. A longer rolling balltravel distance indicated lower tack to the polar surface of the glassball, and indicated that the coating has a lower tendency to stick torollers and metal surfaces on packaging machines, compared to coatingswith a shorter rolling ball travel distance which indicated a highertack level. A longer rolling ball travel distance may also correlate toa lower tendency to adhere to food crumbs. In this measurement, themeasurement was limited to a maximum of 4 inches because the maximumsample size available for testing was 4.0 inches×4.0 inches. Resultsfrom the rolling ball tack test are shown at Table 8.

TABLE 8 Rolling Ball Tack Test Results Samples Rolling Ball Distance(Inches) 17 >4 18 >4 19 ⅛ (PSA-Control)

From the results, it can be seen that the two inventive Samples 17 and18 had lower surface tack than the control, as evidenced by the glassball easily rolling across the surface of the reclosable fastener andoff of the 4 inch long sample. On the contrary, the glass ball stuck tothe PSA-control almost immediately upon contacting the PSA-controlsurface, which was indicative of a high tack surface of the coating.

Example 5

A peel repetition test was performed to test the reseal and peel abilityover multiple repetitions. Approximately twenty samples were made;Samples 20 to 35 were made using the adhesive formulation of Sample 17from Example 4, and Samples 36 to 38 were made using the adhesiveformulation of Sample 18 from Example 4. Samples were produced on acommercial scale pilot coating line via the flexographic coatingprocess. The liquid adhesive coating system was preheated to 160° F.(71° C.) and circulated through a chambered doctor blade which wasmounted to an engraved chromium oxide ceramic roll. The engraved roll(which was also temperature-controlled to 160° F. (71° C.)) transferredthe liquid adhesive coating to a patterned rubber roll. The patternedrubber roll in turn transferred the patterned coating to the movingsubstrate film (i.e., the process illustrated in FIG. 6). After exitingthe coating station, the film traveled through a 60 ft. long ovensection. A UV treater, consisting of 3 banks of UV lamps, was located atthe oven exit. The line configuration with the UV zone located at theexit end of the oven resulted in the maximum path length between thecoating station where the material was applied and the UV curingstation, which maximized the amount of time available for the liquidadhesive coating to flow-out and level, prior to being cured into across-linked polymer network. It is believed that, in some cases, asmooth and level coating surface helps to achieve the desired adhesiveto adhesive peel force in the fully cured adhesive.

A series of experimental coating runs were performed. Line speed, oventemperature, and the number of UV lamp banks were varied. Theexperimental design and experimental observations are summarized inTable 9 below. Visual surface roughness, MEK resistance, and separationof adhesive along the adhesive-to-adhesive bond line of the sample priorto testing were determined. In general, samples produced at 300 ft./min.to 500 ft./min. line speed had a rough surface appearance and low or nosubjective peel force. Instrumented peel force measurement of thesesamples was for the most part not possible because the joined samplesseparated on their own accord before further tests could be carried out.Samples produced at 100 ft./min. had a smooth surface appearance andmoderate adhesive to adhesive peel force. These samples were furthercharacterized using instrumented peel force testing as summarized inTables 10 and 11 to follow. Only the samples that did not separate ontheir own, as shown in Table 9, were tested in the repeated peel-resealtests. These were Samples, 21, 22, 29, 30, 31, 32, 35, 36 and 38.

TABLE 9 Experimental Design Used to Produce Samples for Peel RepetitionTesting Visual MEK Rub Adhesive- Line Oven adhesive Test (# of JoinedSample Based Speed Temperature No. of UV surface double samples No.Sample No. (ft/min) (° F.) lamp banks appearance rubs) separated 20 17(Ex. 4) 500 100 3 Very 15 Yes Rough 21 17 (Ex. 4) 100 100 1 Smooth 100+No 22 17 (Ex. 4) 100 100 3 Smooth 100+ No 23 17 (Ex. 4) 500 100 1 Very 5 Yes Rough 24 17 (Ex. 4) 300 100 2 Very 100+ Yes Rough 25 17 (Ex. 4)500 130 2 Very 60 Yes Rough 26 17 (Ex. 4) 300 130 2 Very 100  Yes Rough27 17 (Ex. 4) 300 130 3 Very 100  Yes Rough 28 17 (Ex. 4) 300 130 1 Very20 Yes Rough 29 17 (Ex. 4) 100 160 1 Smooth 100+ No 30 17 (Ex. 4) 300160 2 Slightly 100+ No Rough 31 17 (Ex. 4) 100 160 2 Smooth 100+ No 3217 (Ex. 4) 100 160 3 Smooth 100+ No 33 17 (Ex. 4) 500 160 1 Very  5 YesRough 34 17 (Ex. 4) 500 160 3 Very 100  No Rough 35 17 (Ex. 4) 100 130 2Smooth 100+ No 36 18 (Ex. 4) 100 160 3 Smooth 100  No 37 18 (Ex. 4) 500160 3 Rough 100  Yes 38 18 (Ex. 4) 300 160 3 Rough 100  No

The first set of peel tests were performed using short intervals betweenpeels, i.e., about three minutes between a peel-reseal cycle. Table 10includes results for this test, where the averages of two samples testedper condition are provided. These results are compared to Sample 19, thePSA-control from Example 4.

TABLE 10 3-Minute Delay Peel-Reseal Test Results Sample 19 Peel StrengthValue (gpli) Peel PSA- Sample Sample Sample Sample Sample Sample SampleSample Sample No. Control 21 22 29 30 31 32 35 36 38 1 459.8 291.8 461.8273.3 148.0 266.7 417.4 418.3 273.9 136.9 2 320.8 74.0 242.1 131.6 32.5129.7 206.3 195.8 527.2 43.0 3 275.0 52.4 204.4 111.5 27.1 112.9 180.8171.9 452.9 44.8 4 254.7 51.8 183.2 107.6 24.2 104.1 158.6 141.6 424.741.1 5 256.9 48.7 161.8 99.2 23.7 102.3 140.5 128.8 404.6 41.8

The second set of peel tests were performed using a longer durationinterval between peels, i.e., about 24 hours between peel-reseal cycles,in order to understand the impact of longer adhesive-adhesive contacttime, with the first peel taking place about one week after the sampleswere prepared. The test results for the extended delay peel-resealsamples are shown at Table 11.

TABLE 11 24-Hour Delay Peel-Reseal Test Results Peel Strength Value(gpli) Sample 19 Peel PSA- Sample Sample Sample Sample Sample SampleSample Sample Sample No. Control 21 22 29 30 31 32 35 36 38 1 539.8271.1 441.7 288.8 149.2 301.9 434.7 432.5 277.3 124 2 521.6 202 362.1238.5 116.2 147 327.6 338.7 447.4 107.3 3 514.6 233.1 349.6 248.3 115.8226.3 297.6 321.6 478.5 106.5 4 550.3 218.2 314.8 222.2 95.5 239 286.5289 493.9 116.8 5 567 231.9 285.9 236.9 95.9 224 299.9 280.4 487.5 125.1

The results show that the samples including adhesive formulation ofSample 17 from Example 4 do not exhibit as pronounced of a decrease inpeel force that typically occur with repeated peels when the durationbetween peels was 24 hours (i.e., Samples 21, 22, 29, 30, 31, 32, and 35in this example). When the adhesive Sample 17 was allowed to remain incontact with itself for about 24 hours between peels, the adhesiverecovered up to about 85% of its original peel force value, even afterfive peel-reseal cycles. Sample 30 had significantly lower average peelforce values compared to the other test samples. Even though the joinedsamples did not separate on their own accord, it had poor surfacesmoothness due to the higher line speed of 300 ft/min.

Furthermore, it was surprising to find that the samples includingadhesive formulations of Sample 18 from Example 4 actually increased inpeel force value (i.e., Sample 36 in this example) with repeated peelsat both the short and long time intervals between peel test cycles,similar to its contamination peel test results in Table 7, evidence of afull recovery of peel force after resealing. Only Sample 36 showed anincrease in peel force value. Sample 36 was the sample cured using theslower line speed, which may have helped to provide a level and smoothsample surface (see Table 9). Sample 38 was made at a higher line speedthan Sample 36 resulting in a rougher surface, which may be why therewas a decrease in peel force value, as well as a low initial peel forcevalue.

In comparison, the PSA-control showed recovery behavior only when theinterval between peels was long, i.e., 24 hours. At the shorter timeinterval, the control actually dropped in peel force, by about 40%.

Overall, for both peel-reseal tests, the best performers were Samples22, 32, 35 and 36. These four samples all correlated to adhesives madewith similar processing conditions. For example, all four samples hadslow line speeds of 100 ft/min, with at least two or more banks of UVlamps turned on. The adhesives that failed the peel-reseal tests likelydid not have sufficient time to flow out and level prior to UV curing.

Example 6

An aging study was conducted using the adhesive Samples 17 and 18 ofExample 4, Table 6 in order to understand the effects of longer adhesiveto adhesive contact time on peel performance. Various properties of theadhesive were tested over a seven-week period including subjectiveinitial peel force (i.e., low, medium, high), visual appearance afterpeeling, subjective tack or tendency to stick to fingers (i.e., none,low, medium, high), coating durability (i.e., MEK solvent resistancetest ASTM D5204), and instrumented peel (i.e., 5 consecutive peelsrepeated on same sample at intervals of about 3 minutes using ASTMD3330/D3330M-04 method F; two samples were tested and averaged together)all at various adhesive to adhesive contact times. The adhesives werecoated onto the same film substrates that were used in Example 2. Table12 below shows the aging results for Sample 17. Table 13 below shows theaging results for Sample 18.

TABLE 12 Summary of Aging Study of Sample 17 Test Performed Day 0 Day 3Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Subjective H H H H H HH H H Initial Peel Force Change in No change No change No change Nochange Spotty Spotty Spotty Spotty Spotty appearance to adhesive toadhesive to adhesive to adhesive surface surface surface surface surfaceafter appearance appearance appearance appearance whitening whiteningwhitening whitening whitening peeling Subjective Low Low Low Low NoneNone None None None Tack MEKRub >100 >100 >100 >100 >100 >100 >100 >100 >100 (# of double rubs)1^(st) Peel 553 567 559 553 463 600 323 505 592 Avg. g/in 2^(nd) Peel370 381 377 382 343 375 241 311 348 Avg. g/in 3^(rd) Peel 339 354 347361 333 352 228 300 335 Avg. g/in 4^(th) Peel 318 342 340 338 330 326232 292 326 Avg. g/in 5^(th) Peel 311 322 326 323 311 297 226 277 317Avg. g/in Avg. Peel 378 393 390 391 356 390 250 337 384 Strength g/in of5 peels

TABLE 13 Effect of Adhesive/Adhesive Contact Time on Repeat PeelPerformance (Sample 18) Test Performed Day 0 Day 3 Week 1 Week 2 Week 3Week 4 Week 5 Week 6 Week 7 Subjective H+ H H H H H H+ H+ H+ InitialPeel Force Appearance No change No change No change No change SurfaceSurface Surface Surface Surface change to adhesive to adhesive toadhesive to adhesive Damage Damage Damage Damage Damage after appearanceappearance appearance appearance peeling Subjective Low Low Low Low NoneNone None None None Tack MEKRub >100 >100 >100 >100 >100 >100 >100 >100 >100 (# of double rubs)1^(st) Peel 781 819 788 800 944 833 819 846 963 Avg. g/in 2^(nd) Peel519 586 567 590 668 377 576 622 556 Avg. g/in 3^(rd) Peel 438 485 510519 428 234 437 485 218 Avg. g/in 4^(th) Peel 399 396 407 409 102 107322 229 105 Avg. g/in 5^(th) Peel 386 358 343 361 64 66 251 134 73 Avg.g/in Avg. Peel 505 529 523 536 441 323 481 463 383 Strength g/in of 5peels

It should be noted that the average peel strength value was an averageof five repeated peels on the same sample that were consecutively peeledat intervals of approximately three minutes. Therefore, the first peelwas determined and the peel strength value recorded, and the reclosablefastener sample was resealed. After three minutes had passed, thereclosable fastener was peeled apart again and the peel force strengthwas recorded. The process was repeated until five peels were performed.

The subjective peel force, subjective tack and MEK rub test results wereall good for both Samples 17 and 18 regardless of the duration of theadhesive to adhesive contact. The peel force values (i.e., initial andsubsequent peels on the same sample) remained consistent for Sample 17regardless of the duration of adhesive to adhesive contact for the rangeof zero days to 7 weeks. Sample 17 showed a much more consistentpeel-reseal cycle than Sample 18. After the initial peel of Sample 17,the loss in adhesive to adhesive bond strength as represented by theloss in peel force upon subsequent peels was generally less than about10% per subsequent peel, and was consistent regardless of the adhesiveto adhesive contact time.

Beginning in week 3, there was a visible change in both Samples 17 and18 (i.e., noticeable whitening and increase in opacity) upon peeling theaged samples. It is believed that this visible change is evidence ofmicroscopic surface deformation of the adhesive due to forces acting onthe adhesive surface during manual or instrumented peeling. The surfacedeformation did not affect the critical performance attributes of theadhesive (i.e., tack or peel strength). In the end, Sample 17 held upslightly better, with its peel strength either increasing over time,i.e., recovering peel strength, or generally maintaining about a 10%peel loss between subsequent peels.

Example 7

The inventive adhesive-based reclosable fastener Sample 17, from Example4, was compared to three other inventive adhesive-based reclosablefasteners, Samples 39 to 41, having the formulations as indicated inTable 14.

TABLE 14 Adhesive-based Fastener Formulations % Component Provided inFinal Adhesive Formulation Adhesive CN 111 US Ricacryl ® CN 3211 BR 144CN 2302 Esacure ® Component (Acrylic 3500 (Tack (Acrylic (Acrylic KTO46Ratio Samples Oligomer) (Elastomer) Agent) Oligomer) Oligomer)(Photoinitiator) (ACR) 17 35 12 50 0 0 3 0.56 (Inventive) 39 27 0 50 200 3 0.94 (Inventive) 40 35 3 39 20 0 3 1.31 (Inventive) 41 15 0 45 20 173 1.16 (Inventive)

Component BR 144 is identified as an acrylic oligomer (BR 144, BomarSpecialties Company, Torrington, Conn.). Component CN 2302 is alsoidentified as an acrylic oligomer (CN 2302, Sartomer Company). All threeSamples, 39 to 41, have incorporated the acrylic oligomer BR 144, withSamples 39 and 40 having two acrylic oligomers and Sample 41 havingthree acrylic oligomers present in the formulation.

The adhesives were coated onto the same film substrates that were usedin Example 2. Samples 39 to 41 were cured at a UV-curing station havingan average line speed of about 25 ft/min and three passes under the UVlamps totaling about 400 mJ/cm2 to about 600 mJ/cm2.

Coating durability of the four adhesives was tested (i.e., MEK solventresistance test ASTM D5204) as well as initial peel strength using ASTMD3330/ D3330M-04 method F. A rolling ball tack test was also performed,which was a modified version of ASTM D3121 as described in Example 4,except the sample size available for testing was about 2.5 inches wideby about 7 inches long. These results are indicated in Table 15.

TABLE 15 Test Results for Cure and Adhesion using Table 14 Formulations.Average Rolling MEK Rub Test Initial Peel Initial Peel Initial Peel Ball(# of double Strength - Strength - Strength Distance Samples rubs) 1(gpli) 2 (gpli) (gpli) (inches) 17 >100 184 191 188 1.5 39 >100 698 733716 6.0 40 >100 341 333 337 >7.0 41 >100 336 289 313 >7.0

The initial peel strength, i.e., initial peel performed under laboratoryconditions, increased for the new formulations by about 30%-300%compared to Sample 17, having only one acrylic oligomer component. Therolling ball tack distance increased for the new formulations by morethan 300% compared to Sample 17.

From the results, it can be seen that the new formulations having two ormore acrylic oligomers had an overall improved performance compared toSample 17, as evidenced by the rolling ball test and the peel strengthtest. All samples had excellent cure rates, evidenced by the MEK rubtest. In particular, all of the new sample formulations, i.e., Samples39 to 41, had lower surface tack than Sample 17 and, in particular,Samples 40 and 41 had an even better low surface tack as evidenced bythe glass ball easily rolling across the surface of the reclosablefastener and off of the 7 inch long sample.

Example 8

The four inventive adhesive-based reclosable fasteners of Example 7 weretested for various repeat peel tests. The samples were initially peeledapart and opened, the peel force was measured in grams per linear inch(gpli) using ASTM test method D3330/D3330M-04 method F, then resealedfor three minutes, and the peel repeated. This seal-reseal was repeatedevery three minutes until ten data points were obtained. The results arepresented below in Table 16.

TABLE 16 Three Minute Peel Delay Test Average Peel Strength (gpli) Peel17 39 40 41 Repetition (Inventive) (Inventive) (Inventive) (Inventive) 1721.4 371 710 388.6 2 525.5 492.4 501.8 517.2 3 477.8 477.1 485.8 442.54 443.6 474.2 459.1 386.7 5 423 478.1 449.6 346.3 6 392.9 480.0 430.2313.7 7 374.5 482.5 411.5 295.4 8 352.6 504.7 397.4 255.9 9 332.6 491.8381.2 224.3 10 326.6 490.3 380.9 204.3

Example 9

A 24-hour delay repeat test was performed using the same four inventivesamples from Example 7. The samples were initially peeled apart andopened, the peel force required being measured. Then the samples areresealed and allowed to sit for 24 hours in a controlled environment,i.e., 72F and 50% relative humidity (RH), until they were repeeled andopened again. This is repeated until a total of five data points havebeen gathered, or for a period of five days. The results are presentedbelow in Table 17.

TABLE 17 24-Hour Peel Delay Test Peel Force (gpli) Initial Peel, SamplesDay 1 Day 2 Day 3 Day 4 Day 5 17 708.1 616.1 582.3 579.4 653.6(Inventive) 39 555.5 641.6 690 752.4 653 (Inventive) 40 811.7 748.6 666614.7 546.9 (Inventive) 41 469.2 513.6 516.8 503.2 479 (Inventive)

All four of the samples maintain their peel performance throughout thefive day test period, without any sample falling below 400 gpli on anyof the test days. Samples 39 and 41 actually increase in peel force andrecover the initial peel force or increase in peel force during the testperiod. Thus, allowing these samples to remain sealed for a period of atleast 24 hours allows these samples to recover or increase inadhesivity.

Example 10

In Example 10, a similar test to Example 9 was performed using the foursamples described in Example 7; however, after each peel opening theadhesive area was contacted with whole coffee beans, resealed, andallowed to remain closed for 24 hours, and repeeled.

After each peel opening, whole coffee beans were placed on the adhesivesurface and removed in less than five minutes. The samples were resealedand allowed to sit for 24 hours in a controlled environment, i.e., 72°F. and 50% RH, until they were repeeled and opened again. This isrepeated until a total of five data points have been gathered, or for aperiod of five days. The results are presented below in Table 18.

TABLE 18 24-Hour Peel Delay Test After Coffee Bean Contamination AveragePeel Force (gpli) Initial Peel, Samples Day 1 Day 2 Day 3 Day 4 Day 5 17695 507 422.1 344.3 271.5 (Inventive) 39 627.3 647 571.2 458.6 294.9(Inventive) 40 770.4 548.3 412.1 327.3 230.4 (Inventive) 41 506.9 476.1382 298.3 211.1 (Inventive)

Although the data shows a slight decrease in peel strength, the peelvalues still exceed 200 gpli after five peel/contamination cycles withwhole coffee beans.

Example 11

A rolling ball tack test as described in Example 4 was performed on filmwith no adhesive for comparison to the tack values of the low tackadhesive. The results are provided below in Table 18. Roll #3 fromSample 1 took a fairly sharp turn shortly after contacting the film.

TABLE 18 Rolling Ball Tack Test On Uncoated Film Sample 1 2 Roll #116.75 15.875 Roll #2 18 18 Roll #3 10.875 14.25 Roll #4 17.25 18.125Roll #5 20.25 19.875 Roll #6 15 AVERAGE 16.35 17.23

It will be understood that various changes in the details, materials,and arrangements of the package and process of formation thereof, whichhave been herein described and illustrated in order to explain thenature of the described package, may be made by those skilled in the artwithin the principle and scope of the embodied method as expressed inthe appended claims.

1. A reclosable package for items, the package comprising: a pluralityof walls sealed to form an interior cavity for receiving the items, thecavity being bounded by a bottom wall segment and an upper mouthinitially sealed, the seal of the mouth being peelably openable topermit initial access to the items in the interior cavity, the pluralityof walls including a pair of opposing wall segments each having top andbottom edge portions, a width, a height and facing inner surfaces; and alow tack adhesive zone disposed on the inner surfaces of each of theopposing wall segments across the entire width of each of the opposingwall segments and extending from adjacent the mouth toward the bottomwall segment along at least a majority of the height of the opposingwall segments, the adhesive zones having a greater affinity for adhesionto each other than to the items and permitting the package to bereclosed using the adhesive zones at a plurality of different heights ofthe opposing wall segments after initial opening of the upper mouth toprogressively decrease the size of the cavity so as to minimize headspace in the reclosed package above the items as the items aresequentially removed from the package.
 2. The reclosable package ofclaim 1, further comprising at least one area of weakness extendinglaterally across a circumference of the package configured to allow aportion of the package adjacent the upper mouth to be removed andthereby reduce extraneous packaging material above at least one of theplurality of different heights.
 3. The reclosable package of claim 1,wherein the package further comprises opposing side wall segments havingfacing inner surfaces, and wherein a low tack adhesive zone is disposedon the inner surfaces of each of the opposing side wall segments.
 4. Areclosable package for items, the package comprising: at least two wallshaving facing inner surfaces, the at least two walls sealed to form atubular package having a circumference, the tubular package initiallysealed on top and bottom edge portions thereof to form an interiorcavity for storing the items; a low tack adhesive disposed in a patternspanning the circumference of the tubular package on aligned portions ofthe facing inner surfaces of the at least two walls intermediate of thetop and bottom edge portions; and wherein the low tack adhesive has agreater affinity for adhesion to itself than to the items effectivelypermitting the package to be reclosed adjacent to the items aftersequential reduction thereof by pressure of the low tack adhesive on thefacing inner surfaces together.
 5. The reclosable package of claim 4,wherein the low tack adhesive is disposed on a majority of the facinginner surfaces.
 6. The reclosable package of claim 4, wherein thepattern of the low tack adhesive comprises a plurality of strips spacedalong the height of the at least two walls and disposed generallytransversely to a longitudinal axis of the package along a circumferenceof the package.
 7. The reclosable package of claim 4, further comprisingat least one area of weakness extending laterally across thecircumference of the package configured to allow a portion of thepackage adjacent the items to be removed and thereby reduce extraneouspackaging material above a reclosed portion of the package.
 8. Thereclosable package of claim 6, further comprising a plurality of areasof weakness extending generally transversely to the longitudinal axis ofthe package along the circumference of the package and disposed aboveand adjacent to the plurality of strips of the low tack adhesive.
 9. Amethod of reclosing a package for items, the method comprising: openingthe package at a peelably openable seal thereof; sequentially removingthe items from the package, thereby creating headspace in the package;reclosing a portion of the package adjacent the items using a low tackadhesive disposed on opposing inner surfaces, thereby decreasing theheadspace in the package.
 10. The method of claim 9, further comprisingremoving a portion of the package adjacent the adhered opposing innersurfaces by separating an area of weakness extending circumferentiallyaround the package adjacent the reclosed portion of the package.